Floating roof for storage tanks



Jan. 29, 1935. A. J. MATTER 1,989,624

FLOATING ROOF FOR STORAGE TANKS Filed July 3, 1933 5 Sheets-Sheet l ATTORNEY Jan. 29, 1935. A. J. MATTER FLOATING ROOF FOR STORAGE TANKS Filed July 3, 1935 SSheets-Sheet 2 INVENTOR Jilbert J Matter ATTORNEY Jan. 29, 1935. A. J. MATTER FLOATING ROOF FOR STORAGE TANKS Filed July 3. 1933 5 Sheets-Sheet 3 INVENTOR filbert J Matter BY ATTORNEY Patented 29, 1935 UNITED STATES PATENT OFFICE.

FLOATING ROOF FOR STORAGE TANKS Albert J. Matter, Park Ridge, 111., allignor of one-half to Standard Oil Company, Chicago, 111., a corporation of Indiana ApplicationJuly 3, 1933, Serial No. 678,838

10 Claims. (Cl. 220-26) This invention relates to storage tanks for the central deck to form independent and subliquids and more particularly to those storage stantially liquid-tight sector shaped comparttanks which are designed to store relatively volaments. On the base of the deck are attached tile liquids and which are therefore constructed suitable supports 4, the function of which is to with a floating roof. support and keep the floating deck at a suitable 5 One of the principal objects of my invention is height above the base of the tank for cleaning to provide a floating roof which will reduce purposes and repairs when the tank is empty. evaporation to a negligible quantity and at the Likewise depending from the base of the deck are same time maybe constructed in such fashion suitable brackets 5 and 6, the purpose of which that all of the elements of the roof blanket the will be described later in the specification. The 10 liquid quite closely and are susceptible to changes outer peripheral edges of the central deck are in level of the liquid. Other objects of my insubstantially vertical as shown by numeral 8. vention will be readily apparent as the following These outer walled surfaces are preferably but specification is read. not necessarily designed to make the central deck In the drawings Figure 1 is a horizontal plan a polygon in horizontal section. The vertical 15 view partially cut away showing the general plates 2 are welded or otherwise suitably joined arrangement of roof and floats. in substantially liquid-tight fashion to a central Figure 2 is a central vertical section partially vertical wall 69. This wall being cylindrical cut away, also showing the general arrangement forms a separ mp r m nt, th ttom f of roof and floats. which 11 is depressed to form a basin or sump. 20

Figure 3 is an enlarged vertical section show- Each of the several main roof sectors communiing with more particularity my arrangement of cates with the central sump by means of a drain floats. pipe 12 provided with a. check valve 18. Liquid Figure 4 is a vertical section through a modified such as rain or snow-water or from a leaky deck type of float. section collects on the deck and is drained oil! 25 Figure 5 is a detailed section taken along the into the sump 11 f m whi h it ma b r ined line' 5 5 of Figure 3, showing the guiding means through a suitable dra a e p p '10 connected to which prevent rotation of the roof as a unit. a conventional swing pipe, not shown, provided Figure 6 is a vertical section taken along the with a conventional check valve not shown.

line 6-6 of Figure 4, showing means for pre- The radial dimensions of the central deck are 30 venting undue sidewise slip between the upper somewhat less than the radius of the tank, leavand lower floats. ing an annular space around the central deck Figure '7 is a vertical section of a detail drawwhich is filled with two series of overlapping ing of the central drainage sump for my floating floats, A and B. Floats B, while independent of roof. the central deck 1, are nevertheless loosely con- 35 Figure 8 is a detail similar to Figure 6 showing a nected to the central deck by means of the chains modified means for preventing the same sidewise 14, the function of which is to support the adjaslip. cent float even ifbecause of some accident the Figure 9 is a vertical section of a modified float should become leaky and tend to sink, one arrangement of floats. end of which is attached to rings 15 on each of 40 Figures 10 and .11 are details showing the means the floats B, and the Other end attached to of attaching the connecting rods with the outer brackets which are welded or otherwise suitably floats. fastened to the vertical wall 8 of the central deck The numeral 60 designates the outer shell of at a point somewhat above the roof 10 of the the liquid storage tank, which is preferably cylincentral deck. The floats B are roughly triangular 45 drical in cross section. The numeral 61 desigin cross section. one side of which, 18, is adapted nates the base of the tank which may be'of any to cooperate in sliding engagement with the outer suitable material. The numeral 1 designates the walls 8 of the central deck. The bottoms 19 of the central portion or deck of the floating roof, being floats B are disposed in sliding engagement with in general a pontoon preferably constructed of the tops 26 of the corresponding floats A, and 50 metal plates suitably welded or riveted together preferably slant upwardly and outwirdly toward to make a substantially liquid tight pontoon the tank wall. Attached to floats B by any suitwhich may be made more rigid by suitable radial able means such as the nut and bolt assembly 59 plates 2 and cross-braces 3. Preferably the plates are brackets 20 which support and cooperate with 2 are welded to the bottom and outer walls of rods 21, one end of which is attached to corre- 55 shaft 21 has a collar and a cotter pin assembly 23.

The floats A, similar to the floats B, are likewise buoyant and roughly of triangularvertical cross section, although I prefer to round of! the inner ends of the floats A as shown at 49. The surfaces 27 of floats A adjacent the shell of the tank are shaped with curved ends 28 to provide elongated surfaces and to enable the floats to ride over any rough or irregular surfaces on the tank wall, such as rivet heads or plate overlaps. The floats B are each provided with an extension plate 50 which is preferably a prolongation of the top 1'7 of said floats. This plate overlaps the adjacent float so as to shield the gap between each two adjacent floats B, thereby reducing evaporation of the stored liquid and lessening the amount of precipitation or dirt which might otherwise seep in between adjacent floats.

Near the bottom of the tank the vertical wall 60 is provided wih an anular horizontal bracket 30, the function of which is to form a support for the floats A when the main deck is resting on the tank bottom for cleaning purposes. At various points within the tank wall there are provided vertical flanges 35 which cooperate with the recessed portions 34 of the elements or pipes 31 which are supported from the main deck by means of the verticalsupports 5 and 6 and which are yieldingly held against the inner surfaces of the tank wall by means of the spring 33, held under compression by the aid of a suitable collar assembly 32. The purpose of these pipes 31 is to prevent horizontal rotation of the entire deck assembly, the pipes 31 being guided by the vertical flanges 35. At such places the bracket 30 is broken broken away as shown in Figure 5.

While in my preferred embodiment in Figure 3 I have shown the bottom surfaces of the floats A as inclined upwardly and outwardly, it may be advantageous under certain conditions to provide a longer bearing surface for the shoe elements or to deflect inwardly such vapors as may tend to collect under the floats A, and to this end, as shown in Figure 4, the floats A may be modified so that the bottom surface is upwardly and inwardly inclined. In this modified type of float the outer surface or shoe 127 is likewise curved inwardly as shown at 128 at both the top and bottom of the shoe, and the innermost end of the float is preferably rounded as shown at 149. A further modification may be employed to prevent undue sidewise slipping or distortion between the two floats 1B and 1A as shown in Figures 4, 6 and 8. This consists in providing the outer floats 1A with vertical flanges 41 which may be suitably welded or otherwise-attached to the upper surfaces of the floats 1A. The bottom surface 218 of the floats 13 may be recessed as shown at 240 in Figure 6, to form a pocket which cooperates with the vertical flanges 41 and prevents undue lateral motion or, on the alternative, as shown in Figure 8 the vertical flanges 41 may be disposed between the side walls of the adjacent inner floats so the floats 2B ride between adjacent vertical flanges 41 as shown in Figure 8. Y

A still further modification of my sealing means is shown in Figure 9. In this modification the outer ring of floats 3A overlaps the inner ring of floats 3B. Floats 3A have upper plates 328, lower plates 329, shoes 32'! provided with elongated ends 328 which give greater sealing surface with the tank shell 360. Floats 33 have upper surfaces 317 which slidably engage the bottoms 329 of floats 3A; the ends 318 of floats 3B are in sliding contact with the walls 808 of the central deck 301; The central deck is loosely connected with the floats 38 by means of safety chains 314 connected to the deck by brackets 309 and to the floats by rings 315. The outer ends of the floats 3B are preferably rounded as shown at 349. Floats 3A are connected to and held in sliding engagement with floats 33 by means of the rods 321 which support the springs 322 under compression between the brackets 320 and the ears 325. The rods are stopped at one end by collars 323 held by cotter pins or other suitable means and are connected to the ears 325 by eyes 324.

The operation of my floating roof is as follows: Since the central deck 1 and the floats A and B are all buoyant, they rise and fall substantially as a unit with the changes in level of the liquid in the tank. The springs 22 being under compression tend to force apart the floats A and B. The floats contact and seal the spaces between the tank, the central deck and themselves at three points, namely the shoes of the floats A contact the inner surface of the tank wall; the adjacent and overlapping surfaces of the floats A and B are in contact; and the inner surfaces 18 of the floats B contact the outer walls 8 of the central deck. There is thus provided a seal which is substantially susceptible to variations in liquid level within the tank and will closely blanket the liquid in the tank, and which will readily form a seal with the tank wall, even though there be imperfections in the inner surface of the wall such as bulges, overlapping plates or rivet heads. The sealing elements are readily accessible for any repairs, easily assembled and replaced in the event of any damage to one or more of the floats. Further advantage is that floats A and B cooperate as a unit independently of the central deck. Consequently even if, because of heavy rain or snow, the central deck becomes loaded and tends to sink to a sub-normal level the peripheral floats are free to rise to their normal level and to function just as efiiciently as though in contact with the central deck of its normal level. This is a distinct advantage over floating roofs which have the shoe members positively connected to the central deck and which are therefore pulled down with the central deck when it becomes partially submerged due to unusual loads. The same functions are performed in a slightly different manner by the modified type of seal shown in Figure 9 in which the outer ring of floats overlaps the inner ring of floats.

It will be understood that changes, modifications and departures may be made from the particular construction described and shown, as this particular embodiment has been chosen merely for illustrative purposes, and the invention as defined by the claims appended hereto may be otherwise embodied and applied without departing from the spirit and scope thereof.

I claim:

1. In a liquid storage tank, a floating roof comprising, a deck having a substantially vertical outer peripheral wall and having a smaller diameter than the shell of the tank, sealing means interposed between and in slidable contact with the inner surface of the tank and the peripheral names;

wall of the deck, said sealing means comprising a plurality of radially movable buoyant outer floats in slidable contact with a pluralityof radially movable buoyant overlapping inner floats, means connecting said inner and said outer floats and tending to force said 'floats apart, said inner floats being so proportioned and related to said outer floats that they receive a substantial buoyant lift from the liquid upon which the roof floats.

2. In a liquid storage tank, a floating roof comprising, a deck having a substantially vertical outer peripheral wall and having a smaller diameter than the shell of the tank, sealing means interposed between and in slidable contact with the inner surface of the tank and the peripheral wall of the deck, said sealing means comprising a plurality of radially movable buoyant outer floats in slidable, contact with a plurality of radially movable overlapping buoyant inner floats, means connecting said inner and said outer floats and tending to force said floats apart, the adiacent surfaces of said outer and inner floats being upwardly and outwardly inclined said inner floats being so proportioned and related to said outer floats that they receive a substantial buoyant lift from the liquid upon which the roof floats.

3. In a liquid storage tank, a floating roof comprising, a deck having a substantially vertical outer peripheral wall and having a smaller diameter than the shell of the tank, sealing means interposed between and in slidable contact with the inner surface of the tank and the peripheral wall of the deck, said sealing means comprising a plurality of partially overlappin buoyant floats disposed in an inner and outer ring, means for yieldingly connecting said outer and inner floats and for maintaining the outer floats in contact with the inner surface of said tank and the inner floats in contact with the peripheral wall of said deck said inner floats being so proportioned and related to said outer floats that they receive a substantial buoyant lift from the liquid upon which the roof floats.

4. In a liquid storage tank, a floating roof comprising, a deck having a substantially vertical outer peripheral wall and having a smaller diameter than the shell of the tank, sealing means interposed between and in slidable contact with the inner surface of the tank and the peripheral wall of the 'deck, said sealing means comprising a plurality of outer buoyant floats in slidable contact with a plurality of overlapping buoyant inner floats, means for yieldingly connecting said out er and inner floats and for maintaining the outer floats in contact with the inner surface of said tank and the inner floats in contact with the peripheral wall of said deck said inner floats being so proportioned and related to said outer floats that they receive a substantial buoyant lift from the liquid upon which the roof floats.

5. In a liquid storage tank, a floating roof comprising, a deck having a substantially vertical outer peripheral wall and having a smaller diameter than the shell of the tank, sealing means interposed between and in slidable contact with the inner surface of the tank and the peripheral wall of the deck, said sealing means comprising a plurality of buoyant outer floats in slidable contact with a plurality of overlapping buoyant inner floats, the adjacent surface of said outer and inner floats being upwardly and outwardly inclined, means for yieldably connecting said outer and inner floats and for maintaining the outer floats in contact with the inner surface of said tank and the inner floats in contact with the peripheral wall of said deck said inner floats being so proportioned and related to said outer floats that they receive a substantial buoyant lift from the liquid upon which the roof floats.

6. In a liquid storage tank, a floating roof comprising, a deck having a substantially vertical outer peripheral wall and having a smaller diameter than the shell of the tank, sealing means interposed between and in slidable contact with the inner surface of the tank and the peripheral wall of the deck, said sealing means comprising a plurality of partially overlapping buoyant floats disposed in an inner and outer ring, spring means for yieldingly connecting said outer and inner floats and for maintaining the outer floats in contact with the inner surface of said tank and the inner floats in contact with the wall of said deck said inner 'floatsbeing so proportioned and related to said outer floats that they receive a substantial buoyant lift from the liquid upon which the roof floats. I

7. In a liquid storage tank, a floating roof comprising, a deck having a substantially vertical outer peripheral wall and having a smaller diameter than the shell of the tank, sealing means interposed between and in slidable contact with the inner surface of the tank and the peripheral wall of the deck, said sealing means comprising a plurality of partially overlapping buoyant floats disposed in an inner and outer ring, means comprising a spring under compression tending to force the outer .and inner floats apart thereby to maintain sealing contact between the outer float and the inner surface of said tank and the inner floats with the peripheral wall of said deck respectively, said inner floats being so proportioned and related to said outer floats that they receive a substantial buoyant lift from the liquid upon which the roof floats.

8. In a liquid storage tank, a floating roof comprising, a deck having a substantially vertical outer peripheral wall and having a smaller diameter than the shell of the tank, sealing means interposed between and in slidable contact with the inner surface of the tank and the peripheral wall of the deck, said sealing means comprising a plurality of buoyant outer floats in slidable contact with a plurality of overlapping buoyant inner floats, means for yieldingly connecting said inner and said outer floats, said outer floats being provided with elongated shoe members whereby to provide greater contact area between the outer floats and the inner surface of the tank said inner floats being so proportioned and related to said outer floats that they receive a substantial buoyant lift from the liquid upon which the roof floats.

9. In a liquid storage tank, a floating roof comprising, a deck having a substantially vertical outer peripheral wall and having a smaller diameter than the shell of the tank, sealing means interposed between and in slidable contact with the inner surface of the tank and the peripheral wall of the deck, said sealing means comprising a plurality of outer floats in slidable contact with a plurality of overlappin inner floats, said outer floats being provided with spaced vertical flanges at intervals slightly greater than the width of the inner floats whereby the inner floats engage in sliding contact with the outer floats between said vertical flanges and whereby the inner floats are prevented from horizontal disalignment.

10. In a liquid storage tank, a. floating roof comprising, a deck having a smaller diameter than the shell of the tank, sealing means interposed between and in slidable contact with the inner overlapping the floats in.the outer ring being surface of the tank and the peripheral wall of yieldinzly connected therewith, said inner floatsthe deck. said sealing means comprising an exbeing so proportioned and related to said outer pansible and contractible outer ring of buoyant floats that they receive a substantial buoyant lift 5 floats and an expansible and contractible inner from the liquid upon which the roof floats.

ring of buoyant floats, the floats in the inner ring ALBERT J. MA'I'I'ER. 

